Source code for torchaudio.backend.sox_io_backend
import os
from typing import Tuple, Optional
import torch
import torchaudio
from torchaudio._internal import (
module_utils as _mod_utils,
)
from .common import AudioMetaData
[docs]@_mod_utils.requires_sox()
def info(
filepath: str,
format: Optional[str] = None,
) -> AudioMetaData:
"""Get signal information of an audio file.
Args:
filepath (path-like object or file-like object):
Source of audio data. When the function is not compiled by TorchScript,
(e.g. ``torch.jit.script``), the following types are accepted;
* ``path-like``: file path
* ``file-like``: Object with ``read(size: int) -> bytes`` method,
which returns byte string of at most ``size`` length.
When the function is compiled by TorchScript, only ``str`` type is allowed.
Note:
* When the input type is file-like object, this function cannot
get the correct length (``num_samples``) for certain formats,
such as ``mp3`` and ``vorbis``.
In this case, the value of ``num_samples`` is ``0``.
* This argument is intentionally annotated as ``str`` only due to
TorchScript compiler compatibility.
format (str or None, optional):
Override the format detection with the given format.
Providing the argument might help when libsox can not infer the format
from header or extension.
Returns:
AudioMetaData: Metadata of the given audio.
"""
if not torch.jit.is_scripting():
if hasattr(filepath, "read"):
sinfo = torchaudio._torchaudio.get_info_fileobj(filepath, format)
return AudioMetaData(*sinfo)
filepath = os.fspath(filepath)
sinfo = torch.ops.torchaudio.sox_io_get_info(filepath, format)
return AudioMetaData(*sinfo)
[docs]@_mod_utils.requires_sox()
def load(
filepath: str,
frame_offset: int = 0,
num_frames: int = -1,
normalize: bool = True,
channels_first: bool = True,
format: Optional[str] = None,
) -> Tuple[torch.Tensor, int]:
"""Load audio data from file.
Note:
This function can handle all the codecs that underlying libsox can handle,
however it is tested on the following formats;
* WAV, AMB
* 32-bit floating-point
* 32-bit signed integer
* 24-bit signed integer
* 16-bit signed integer
* 8-bit unsigned integer (WAV only)
* MP3
* FLAC
* OGG/VORBIS
* OPUS
* SPHERE
* AMR-NB
To load ``MP3``, ``FLAC``, ``OGG/VORBIS``, ``OPUS`` and other codecs ``libsox`` does not
handle natively, your installation of ``torchaudio`` has to be linked to ``libsox``
and corresponding codec libraries such as ``libmad`` or ``libmp3lame`` etc.
By default (``normalize=True``, ``channels_first=True``), this function returns Tensor with
``float32`` dtype and the shape of `[channel, time]`.
The samples are normalized to fit in the range of ``[-1.0, 1.0]``.
When the input format is WAV with integer type, such as 32-bit signed integer, 16-bit
signed integer, 24-bit signed integer, and 8-bit unsigned integer, by providing ``normalize=False``,
this function can return integer Tensor, where the samples are expressed within the whole range
of the corresponding dtype, that is, ``int32`` tensor for 32-bit signed PCM,
``int16`` for 16-bit signed PCM and ``uint8`` for 8-bit unsigned PCM. Since torch does not
support ``int24`` dtype, 24-bit signed PCM are converted to ``int32`` tensors.
``normalize`` parameter has no effect on 32-bit floating-point WAV and other formats, such as
``flac`` and ``mp3``.
For these formats, this function always returns ``float32`` Tensor with values normalized to
``[-1.0, 1.0]``.
Args:
filepath (path-like object or file-like object):
Source of audio data. When the function is not compiled by TorchScript,
(e.g. ``torch.jit.script``), the following types are accepted;
* ``path-like``: file path
* ``file-like``: Object with ``read(size: int) -> bytes`` method,
which returns byte string of at most ``size`` length.
When the function is compiled by TorchScript, only ``str`` type is allowed.
Note: This argument is intentionally annotated as ``str`` only due to
TorchScript compiler compatibility.
frame_offset (int):
Number of frames to skip before start reading data.
num_frames (int, optional):
Maximum number of frames to read. ``-1`` reads all the remaining samples,
starting from ``frame_offset``.
This function may return the less number of frames if there is not enough
frames in the given file.
normalize (bool, optional):
When ``True``, this function always return ``float32``, and sample values are
normalized to ``[-1.0, 1.0]``.
If input file is integer WAV, giving ``False`` will change the resulting Tensor type to
integer type.
This argument has no effect for formats other than integer WAV type.
channels_first (bool, optional):
When True, the returned Tensor has dimension `[channel, time]`.
Otherwise, the returned Tensor's dimension is `[time, channel]`.
format (str or None, optional):
Override the format detection with the given format.
Providing the argument might help when libsox can not infer the format
from header or extension.
Returns:
(torch.Tensor, int): Resulting Tensor and sample rate.
If the input file has integer wav format and normalization is off, then it has
integer type, else ``float32`` type. If ``channels_first=True``, it has
`[channel, time]` else `[time, channel]`.
"""
if not torch.jit.is_scripting():
if hasattr(filepath, "read"):
return torchaudio._torchaudio.load_audio_fileobj(
filepath, frame_offset, num_frames, normalize, channels_first, format
)
filepath = os.fspath(filepath)
return torch.ops.torchaudio.sox_io_load_audio_file(
filepath, frame_offset, num_frames, normalize, channels_first, format
)
[docs]@_mod_utils.requires_sox()
def save(
filepath: str,
src: torch.Tensor,
sample_rate: int,
channels_first: bool = True,
compression: Optional[float] = None,
format: Optional[str] = None,
encoding: Optional[str] = None,
bits_per_sample: Optional[int] = None,
):
"""Save audio data to file.
Args:
filepath (str or pathlib.Path): Path to save file.
This function also handles ``pathlib.Path`` objects, but is annotated
as ``str`` for TorchScript compiler compatibility.
src (torch.Tensor): Audio data to save. must be 2D tensor.
sample_rate (int): sampling rate
channels_first (bool, optional): If ``True``, the given tensor is interpreted as `[channel, time]`,
otherwise `[time, channel]`.
compression (float or None, optional): Used for formats other than WAV.
This corresponds to ``-C`` option of ``sox`` command.
``"mp3"``
Either bitrate (in ``kbps``) with quality factor, such as ``128.2``, or
VBR encoding with quality factor such as ``-4.2``. Default: ``-4.5``.
``"flac"``
Whole number from ``0`` to ``8``. ``8`` is default and highest compression.
``"ogg"``, ``"vorbis"``
Number from ``-1`` to ``10``; ``-1`` is the highest compression
and lowest quality. Default: ``3``.
See the detail at http://sox.sourceforge.net/soxformat.html.
format (str or None, optional): Override the audio format.
When ``filepath`` argument is path-like object, audio format is infered from
file extension. If file extension is missing or different, you can specify the
correct format with this argument.
When ``filepath`` argument is file-like object, this argument is required.
Valid values are ``"wav"``, ``"mp3"``, ``"ogg"``, ``"vorbis"``, ``"amr-nb"``,
``"amb"``, ``"flac"``, ``"sph"``, ``"gsm"``, and ``"htk"``.
encoding (str or None, optional): Changes the encoding for the supported formats.
This argument is effective only for supported formats, such as ``"wav"``, ``""amb"``
and ``"sph"``. Valid values are;
- ``"PCM_S"`` (signed integer Linear PCM)
- ``"PCM_U"`` (unsigned integer Linear PCM)
- ``"PCM_F"`` (floating point PCM)
- ``"ULAW"`` (mu-law)
- ``"ALAW"`` (a-law)
Default values
If not provided, the default value is picked based on ``format`` and ``bits_per_sample``.
``"wav"``, ``"amb"``
- | If both ``encoding`` and ``bits_per_sample`` are not provided, the ``dtype`` of the
| Tensor is used to determine the default value.
- ``"PCM_U"`` if dtype is ``uint8``
- ``"PCM_S"`` if dtype is ``int16`` or ``int32``
- ``"PCM_F"`` if dtype is ``float32``
- ``"PCM_U"`` if ``bits_per_sample=8``
- ``"PCM_S"`` otherwise
``"sph"`` format;
- the default value is ``"PCM_S"``
bits_per_sample (int or None, optional): Changes the bit depth for the supported formats.
When ``format`` is one of ``"wav"``, ``"flac"``, ``"sph"``, or ``"amb"``, you can change the
bit depth. Valid values are ``8``, ``16``, ``32`` and ``64``.
Default Value;
If not provided, the default values are picked based on ``format`` and ``"encoding"``;
``"wav"``, ``"amb"``;
- | If both ``encoding`` and ``bits_per_sample`` are not provided, the ``dtype`` of the
| Tensor is used.
- ``8`` if dtype is ``uint8``
- ``16`` if dtype is ``int16``
- ``32`` if dtype is ``int32`` or ``float32``
- ``8`` if ``encoding`` is ``"PCM_U"``, ``"ULAW"`` or ``"ALAW"``
- ``16`` if ``encoding`` is ``"PCM_S"``
- ``32`` if ``encoding`` is ``"PCM_F"``
``"flac"`` format;
- the default value is ``24``
``"sph"`` format;
- ``16`` if ``encoding`` is ``"PCM_U"``, ``"PCM_S"``, ``"PCM_F"`` or not provided.
- ``8`` if ``encoding`` is ``"ULAW"`` or ``"ALAW"``
``"amb"`` format;
- ``8`` if ``encoding`` is ``"PCM_U"``, ``"ULAW"`` or ``"ALAW"``
- ``16`` if ``encoding`` is ``"PCM_S"`` or not provided.
- ``32`` if ``encoding`` is ``"PCM_F"``
Supported formats/encodings/bit depth/compression are;
``"wav"``, ``"amb"``
- 32-bit floating-point PCM
- 32-bit signed integer PCM
- 24-bit signed integer PCM
- 16-bit signed integer PCM
- 8-bit unsigned integer PCM
- 8-bit mu-law
- 8-bit a-law
Note: Default encoding/bit depth is determined by the dtype of the input Tensor.
``"mp3"``
Fixed bit rate (such as 128kHz) and variable bit rate compression.
Default: VBR with high quality.
``"flac"``
- 8-bit
- 16-bit
- 24-bit (default)
``"ogg"``, ``"vorbis"``
- Different quality level. Default: approx. 112kbps
``"sph"``
- 8-bit signed integer PCM
- 16-bit signed integer PCM
- 24-bit signed integer PCM
- 32-bit signed integer PCM (default)
- 8-bit mu-law
- 8-bit a-law
- 16-bit a-law
- 24-bit a-law
- 32-bit a-law
``"amr-nb"``
Bitrate ranging from 4.75 kbit/s to 12.2 kbit/s. Default: 4.75 kbit/s
``"gsm"``
Lossy Speech Compression, CPU intensive.
``"htk"``
Uses a default single-channel 16-bit PCM format.
Note:
To save into formats that ``libsox`` does not handle natively, (such as ``"mp3"``,
``"flac"``, ``"ogg"`` and ``"vorbis"``), your installation of ``torchaudio`` has
to be linked to ``libsox`` and corresponding codec libraries such as ``libmad``
or ``libmp3lame`` etc.
"""
if not torch.jit.is_scripting():
if hasattr(filepath, "write"):
torchaudio._torchaudio.save_audio_fileobj(
filepath, src, sample_rate, channels_first, compression, format, encoding, bits_per_sample
)
return
filepath = os.fspath(filepath)
torch.ops.torchaudio.sox_io_save_audio_file(
filepath, src, sample_rate, channels_first, compression, format, encoding, bits_per_sample
)
